LITTLE ROCK, Ark. (Reuters) - Arkansas Governor Asa Hutchinson endorsed a measure on Wednesday to have the state honor civil rights leader Martin Luther King and Confederate General Robert E. Lee on separate days, rather than together, but said passing it would be an uphill battle.

The Republican governor has been pushing to separate the joint celebration, in effect since 1985, after critics said it was an insult to the memory of King, who battled to end racial segregation, to share a day with a man who fought to preserve slavery.

"It gives us a chance to show respect for one another," Hutchinson told a news conference.

He added it would not be easy to pass the bill in the Republican-controlled legislature even with his backing, although adding several key Republican lawmakers backed the effort.

Arkansas in the 1940s set up a day in mid-January to honor Lee. The state was a member of the Southern Confederacy during the 1861-1865 Civil War. It created a holiday for King in 1983. Two years later, it combined the two for a joint day marked on the third Monday in January.

"When we merged the two holidays, we gave the people of Arkansas a choice, General Lee or Dr. King. That was a false choice," Hutchinson said.

Under proposed legislation endorsed by Hutchinson, the state would honor King on the national holiday in January for the slain civil rights leader. The second Saturday in October would be designated a "memorial day" for Lee but would not be a state holiday.

Mississippi and Alabama are the only other states to honor the two men jointly.Their birthdays are only a few days apart in January.

Hutchinson tried to separate the joint day in 2015 but the effort sputtered amid protests from Confederate history enthusiasts and cultural conservatives.

In an attempt to defuse opposition, the bill specifies that Arkansas public schools instruct students in "civilian and military leadership" during the Civil War as well as the civil rights movement.

"Arkansas has got to realize it's time to separate the two and make that day for Dr. King," said David Wallace, a Republican state senator and one of two primary sponsors of the bill.